
STARTING AND OPERATING
142
Diesel Engine Idling — In Cold Weather
Avoid  prolonged  idling  in  ambient  tempera-
tures  below  0°F  (-18°C).  Long  periods  of
idling  may  be  harmful  to  your  engine
because  combustion  chamber  temperatures
can  drop  so  low  that  the  fuel  may  not  burn
completely.  Incomplete  combustion  allows
carbon  and  varnish  to  form  on  piston  rings
and injector nozzles. Also, the unburned fuel
can enter the crankcase, diluting the oil and
causing rapid wear to the engine.
Stopping the Engine
The  following  chart  should  be  used  as  a
guide  in  determining  the  amount  of  engine
idle  time  required  to  sufficiently  cool  down
the  turbocharger  before  shut  down,
depending  upon  the  type  of  driving  and  the
amount of cargo.
Before  turning  off  your  turbo  diesel  engine,
always allow the engine to return to normal idle
speed  and  run  for  several  seconds.  This
ensures proper lubrication of the turbocharger. This  is  particularly  necessary  after  any  period
of hard driving.
Idle the engine a few minutes before routine
shutdown.  After  full load operation, idle  the
engine three to five  minutes before shutting
it down. This idle period will allow the lubri
-
cating  oil  and  coolant  to  carry  excess  heat
away  from  the  combustion  chamber,  bear -
ings,  internal  components,  and  turbo -
charger.  This  is  especially  important  for
turbocharged, charge air cooled engines.
Turbocharger "Cool Down" Chart
Driving
Conditions Load
Turbocharger
Temperature Idle Time (In Minutes)
Before Shut Down
Stop & Go EmptyCoolLess than 1
Stop & Go Medium Warm1
Highway Speeds MediumWarm2
City Traffic Max. GCWR Warm3
Highway Speeds Max. GCWR Warm4
Uphill Grade Max. GCWR Hot5
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143
(Continued)
ENGINE BREAK-IN 
RECOMMENDATIONS
A long break-in period is not required for the
engine and drivetrain (transmission and axle)
in your vehicle.
Drive  moderately  during  the  first  300 miles
(500 km).  After  the  initial  60 miles
(100 km), speeds up to 50 or 55 mph (80 or
90 km/h) are desirable.
While  cruising,  brief  full-throttle  accelera-
tion  within  the  limits  of  local  traffic  laws
contributes  to  a  good  break-in.  Wide-open
throttle acceleration in low gear can be detri -
mental and should be avoided.
The engine oil installed in the engine at the
factory  is  a  high-quality  energy  conserving
type lubricant. Oil changes should be consis -
tent  with  anticipated  climate  conditions
under which vehicle operations will occur.
For  the  recommended  viscosity  and  quality
grades,  refer  to  “Fluids  And  Lubricants”  in
“Technical Specifications”. NOTE:
A new engine may consume some oil during
its  first  few  thousand  miles  (kilometers)  of
operation.  This  should  be  considered  a
normal  part  of  the  break-in  and  not  inter
-
preted as a problem.
AUTOMATIC 
TRANSMISSION  
NOTE:
You  must  press  and  hold  the  brake  pedal
while shifting out of PARK. CAUTION!
Never  use  Non-Detergent  Oil  or  Straight
Mineral  Oil  in  the  engine  or  damage  may
result.
 CAUTION!
Shift  into  or  out  of  PARK  or  REVERSE
only  after  the  vehicle  has  come  to  a
complete stop.
Do  not  shift  between  PARK,  REVERSE,
NEUTRAL, or DRIVE when the engine is
above idle speed.
Before shifting into any gear, make sure
your  foot  is  firmly  pressing  the  brake
pedal.
 WARNING!
Never use the PARK position as a substi -
tute for  the parking brake. Always  apply
the parking brake fully when exiting the
vehicle  to  guard  against  vehicle  move-
ment and possible injury or damage.
Your  vehicle  could  move  and  injure  you
and others if it is not in PARK. Check by
trying  to  move  the  transmission  gear
selector  out  of  PARK  with  the  brake
pedal released. Make sure the transmis-
sion  is  in  PARK  before  exiting  the
vehicle.
The transmission may not engage PARK
if the vehicle is moving. Always bring the
vehicle  to  a  complete  stop  before
shifting  to  PARK,  and  verify  that  the
transmission  gear  position  indicator
solidly  indicates  PARK  (P)  without
blinking.  Ensure  that  the  vehicle  is
completely stopped, and the PARK posi -
tion is properly indicated, before exiting
the vehicle.
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183
(Continued)
Center High Mounted Stop Lamp (CHMSL) 
Please see an authorized dealer for service.
License Plate Lamps
1. Reach  under  the  vehicle  to  access  theback of the lamp.
2. Firmly  grasp  the  bulb  by  the  two  latch features  and  squeeze  them  together  to
unlock  the  bulb  from  the  back  of  the
lamp housing.
Rear Fog Lamp
NOTE:
We  advise  referring  to  an  authorized  dealer
for service.
1. Reach  under  the  vehicle  to  access  theback of the fog lamp.
2. Disconnect  the  wire  harness  connector from the fog lamp connector receptacle.
3. Rotate the socket a quarter turn counter -
clockwise,  then  remove  it  from  the
housing.
4. Pull the bulb straight out from the keyed opening in the housing and then connect
the replacement bulb and reassemble.
FUSES 
General Information
The  fuses  protect  electrical  systems  against
excessive current.
When  a  device  does  not  work,  you  must
check the fuse element inside the blade fuse
for a break/melt.
Also, please be aware that when using power
outlets for extended periods of time with the
engine  off  may  result  in  vehicle  battery
discharge.
 CAUTION!
Do  not  touch  the  new  bulb  with  your
fingers.  Oil  contamination  will  severely
shorten  bulb  life.  If  the  bulb  comes  in
contact  with  any  oily  surface,  clean  the
bulb with rubbing alcohol.
 WARNING!
When replacing a blown fuse, always use
an  appropriate  replacement  fuse  with
the same amp rating as the original fuse.
Never replace a fuse with another fuse of
higher amp rating. Never replace a blown
fuse with metal wires or any other mate-
rial.  Failure  to  use  proper  fuses  may
result in serious personal injury, fire and/
or property damage.
Before  replacing  a  fuse,  make sure  that
the  ignition  is  off  and  that  all  the  other
services  are  switched  off  and/or  disen -
gaged.
If the replaced fuse blows again, contact
an authorized dealer.
If  a  general  protection  fuse  for  safety
systems  (air  bag  system,  braking
system),  power  unit  systems  (engine
system,  gearbox  system)  or  steering
system  blows,  contact  an  authorized
dealer.
 CAUTION!
If  it  is  necessary  to  wash  the  engine
compartment,  take  care  not  to  directly  hit
the  fuse  box,  and  the  windshield  wiper
motors with water.
 WARNING! (Continued)
2020_JEEP_JL_WRANGLER_UG_RHD_UK.book  Page 183   

210
SERVICING AND MAINTENANCE
SCHEDULED SERVICING 
Correct servicing is crucial for guaranteeing a
long  life  for  the  car  under  the  best  condi-
tions.  For  this  reason,  Jeep  has  planned  a
series  of  checks  and  services  at  fixed
distance  intervals  and,  where  provided,  at
fixed  time  intervals,  as  described  in  the
Scheduled Servicing plan. To keep the car’s
efficiency  in  tip-top  condition,  in  the
following  Scheduled  Service  plan  pages  a
few  additional  checks  are  listed  that should
be  carried  out  more  frequently  with  respect
to  the  normal  coupon redemption schedule.
Scheduled Servicing is offered by  all autho -
rized  dealerships  according  to  fixed  time  or
mileage intervals.  If,  during  each operation,
in  addition to the  ones  scheduled, the need
arises  for  further  replacements  or  repairs,
these  may  be  carried  out  with  the  owner's
explicit agreement only.
The technicians at your dealership know your
vehicle  best,  and  have  access  to  factory
trained  information,  genuine  Mopar  parts,
and  specially  designed  electronic  and
mechanical  tools  that  can  help  prevent
future  costly  repairs.  If  your  car  is  used
frequently  for  towing,  the  interval  between
one  scheduled  servicing  operation  and  the next should be reduced. More frequent main
-
tenance may be needed for vehicles in severe
operating  conditions,  such  as  dusty  areas
and very short trip driving.
NOTE:
Scheduled  Servicing  interventions  are  set
out  by  the  Manufacturer.  Failure  to  have
them  carried  out  may  invalidate  the
warranty.  It  is  advised  to  inform  an  autho -
rized dealership of any small operating irreg -
ularities without waiting for the next service.
Scheduled Servicing — Gasoline Engine  
The  oil  change  indicator  system  (if
equipped)  will  remind  you  that  it  is  time  to
take  your  vehicle  in  for  engine  oil  replace -
ment.
On  vehicles  equipped  with  instrument
cluster  display,  “Oil  Change  Required”  will
be displayed and a single chime will  sound,
indicating that an oil change is necessary.
On non-instrument cluster display equipped
vehicles,  “Change  Oil”  will  flash  in  the
instrument  cluster  odometer  and  a  single
chime  will  sound,  indicating  that  an  oil
change is necessary. The oil change indicator message will illumi
-
nate  approximately  7,000 miles
(11,200 km)  after  the  most  recent  oil
change  was  performed.  Have  your  vehicle
serviced  as  soon  as  possible,  within
500 miles (800 km). However, an earlier oil
change  at  4,500 miles  (7,500 km)  may  be
required  if  the  vehicle  is  operated  under
“Severe  Duty  Conditions”  later  in  this
section.
NOTE:
The oil change indicator message will not
monitor the time since the last oil change.
Change  your  vehicle's  oil  if  it  has  been
12 months since your last oil change even
if the oil change indicator message is NOT
illuminated.
Change  your  engine  oil  more  often  if  you
drive your vehicle off-road for an extended
period of time.
Under no circumstances should oil change
intervals  exceed  7,500 miles
(12,000 km)  or  12 months,  whichever
comes first.
An authorized dealer will reset the oil change
indicator  message  after  completing  the
scheduled oil change.
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211
Once A Month Or Before A Long Trip
Check  the  engine  oil  level  about  five
minutes  after  a  fully  warmed  engine  is
shut  off.  Checking  the  oil  level  while  the
vehicle is on level ground will improve the
accuracy  of  the  oil  level  reading.  Add  oil
only when the level is at or below the ADD
or MIN mark.
Check  the  windshield  washer  solvent  and
add if required.
Check  tire  pressure  and  look  for  unusual
wear  or  damage.  Rotate  tires  at  the  first
sign of irregular wear.
Inspect the battery and clean and tighten
the terminals as required.
Check the fluid levels of coolant reservoir,
brake  master  cylinder  and  power  steering
and fill as needed.
Check all lights and other electrical items
for correct operation.At Each Oil Change
Change the engine oil filter.
Inspect the brake hoses and lines.
Inspect the CV/Universal joints.
Check  tire  pressure  and  look  for  unusual
wear  or  damage.  Rotate  tires  at  the  first
sign  of  irregular  wear,  even  if  it  occurs
before the oil indicator system turns on.
Required Maintenance Intervals
Refer  to  the  Maintenance  Plan  on  the
following pages for the required maintenance
intervals.
Maintenance Plan
NOTE:
Once you have carried out the  last interven -
tion  in  the  table,  continue  with  the  sched -
uled  servicing,  maintaining  the  frequency
indicated in the plan by marking each oper -
ation  with  a  dot  or  dedicated  note.  Simply
restarting the maintenance from the start of
the plan may cause the allowed interval to be
exceeded for some operations.
 CAUTION!
Failure  to  perform  the  required
maintenance  items  may  result  in  damage
to the vehicle.
2020_JEEP_JL_WRANGLER_UG_RHD_UK.book  Page 211   

SERVICING AND MAINTENANCE
212Mileage or time passed 
(whichever comes first)
7,500
15,000
22,500
30,000
37,500
45,000
52,500
60,000
67,500
75,000
82,500
90,000
97,500
105,000
112,500
120,000
127,500
135,000
142,500
150,000
Or Months: 12 24 36 48 60 72 84 96 108 120 132 144 156 168 180 192 204 216 228 240
Or Kilometers:
12,000
24,000
36,000
48,000
60,000
72,000
84,000
96,000
108,000
120,000
132,000
144,000
156,000
168,000
180,000
192,000
204,000
216,000
228,000
240,000
Change engine oil and 
oil filter. * X X X X X X X X X X X X X X X X X X X X
Rotate tires X X X X X X X X X X X X X X X X X X X X
Inspect all door latches 
for presence of grease, 
reapply if necessary. X X X X X X X X X X X X X X X X X X X X
If using your vehicle for 
any of the following: 
Dusty or off-road 
conditions. Inspect the 
engine air cleaner filter, 
replace if necessary. X X X X X X X X X X
Inspect the brake 
linings, replace if 
necessary. X X X X X X X X X X
Inspect exhaust system. XX X XXX
2020_JEEP_JL_WRANGLER_UG_RHD_UK.book  Page 212   

SERVICING AND MAINTENANCE
216
Severe Duty Conditions
Change the engine oil and engine oil filter at
every  4,500 miles  (7,500 km)  or  6 months
if  using  your  vehicle  under  any  of  the
following severe duty conditions:
Stop and go driving.
Driving in dusty conditions.
Short trips of less than 10 miles (16 km).
Trailer towing.
Taxi,  police,  or  delivery  service  (commer-
cial service).
Off-road or desert operation.
Scheduled Servicing — Diesel Engine  
Your  vehicle  is  equipped  with  an  automatic
oil  change  indicator  system.  The  oil  change
indicator  system  will  remind  you  that  it  is
time  to  take  your  vehicle  in  for  engine  oil
replacement.
On  vehicles  equipped  with  instrument
cluster  display,  “Oil  Change  Required”  will
be displayed and a single chime will  sound,
indicating that an oil change is necessary.
On non-instrument cluster display equipped
vehicles,  “Change  Oil”  will  flash  in  the
instrument  cluster  odometer  and  a  single
chime  will  sound,  indicating  that  an  oil
change is necessary.
Based  on  engine  operation  conditions,  the  oil
change indicator message will illuminate. This
means that service is required for your vehicle.
Operating  conditions  such  as  frequent
short-trips,  trailer  tow,  extremely  hot  or  cold
ambient  temperatures  will  influence  when  the
“Oil  Change  Required”  message  is  displayed. Severe  Operating  Conditions  can  cause  the
change oil message to illuminate as earlier than
specified.  Have  your  vehicle  serviced  as  soon
as  possible,  within  the  next  500 miles
(805 km).
NOTE:
The actual interval for changing engine oil
and replacing the engine oil filter depends
on  the  vehicle  usage  conditions,  and  is
signaled  by  the  warning  light  or  message
in  the  instrument  panel.  In  any  case,  it
must  never  exceed  12,500 miles
(20,000 km) or 1 year
Flush  and  replace  the  engine  coolant  at
120 months or 150,000 miles (240,000 km)
whichever comes first.
The  maximum  mileage  is  75,000 mi
(120,000 km).  The  belt  must  be  replaced
every  5  years  regardless  of  distance  trav-
eled. The timing and accessory belts must be
changed every 37,500 miles (60,000 km) or
3  years  for  particularly  demanding  use
(dusty  areas,  severe  weather  conditions,
very  low  or  very  high  temperatures  for
extended  periods,  city  driving,  long  periods
of  idling).  Under  no  circumstances  should
these intervals be exceeded.
 WARNING!
You  can  be  badly  injured  working  on  or
around  a  motor  vehicle.  Do  only  service
work  for  which  you  have  the  knowledge
and the right equipment. If you have any
doubt  about  your  ability  to  perform  a
service job, take your vehicle to a compe-
tent mechanic.
Failure to properly inspect and maintain
your vehicle could result in a component
malfunction and effect vehicle handling
and  performance.  This  could  cause  an
accident.
2020_JEEP_JL_WRANGLER_UG_RHD_UK.book  Page 216   

217
Once A Month Or Before A Long Trip
Check engine oil level.
Check windshield washer fluid level.
Check  tire  pressure  and  look  for  unusual
wear  or  damage.  Rotate  tires  at  the  first
sign  of  irregular  wear,  even  if  it  occurs
before the oil indicator system turns on.
Check the fluid levels of the coolant reservoir
and brake master cylinder, fill as needed.
Check function of all interior and exterior lights.Demanding Vehicle Use
Restore  additive level for  AdBlue® Diesel
emissions (UREA) (if equipped), when the
lamp is illuminated or the message on the
instrument panel.
Maintenance Plan — Diesel Engine
Required Maintenance Intervals
Refer  to  the  maintenance  plan  on  the
following pages for the required maintenance
intervals.
NOTE:
Once you have carried out the last intervention in the table, continue with the scheduled servicing, maintaining the frequency indicated in
the plan by marking each operation with a dot or dedicated note. Simply restarting the maintenance from the start of the plan may cause the
allowed interval to be exceeded for some operations.
 CAUTION!
Failure  to  perform  the  required  maintenance
items may result in damage to the vehicle.
At Every Oil Change Interval As Indicated By Oil Change Indicator System:
Change oil and filter
Rotate the tires.  Rotate at the first sign of irregular wear, even if it occurs before the oil indicator system turns on
Inspect battery and clean and tighten terminals as required
Inspect the CV/Universal joints
Inspect brake pads, shoes, rotors, drums, hoses and park brake
Inspect engine cooling system protection and hoses
Inspect exhaust system
Inspect engine air cleaner if using in dusty or off-road conditions
Inspect all door latches for presence of grease, reapply if necessary.
Inspect coolant level.
2020_JEEP_JL_WRANGLER_UG_RHD_UK.book  Page 217